date now has a default nil value

app/controllers/people_controller.rb

@@ -52,7 +52,8 @@ class PeopleController < ApplicationController
   def update
     # convert date selector into proper timestamp
     birthday = params[:date]
-    if birthday
+    
+    unless [:month, :day, :year].any?{|x| birthday[x].blank?} 
       params[:person][:profile][:birthday] ||= Date.parse("#{birthday[:year]}-#{birthday[:month]}-#{birthday[:day]}")
     end
 

app/models/aspect.rb

@@ -29,7 +29,7 @@ class Aspect
   def to_s
     name
   end
-
+  
   def person_objects
     person_ids = people.map{|x| x.person_id}
     Person.all(:id.in => person_ids)

app/views/people/edit.html.haml

@@ -34,7 +34,7 @@
       %h4
         = t('.your_birthday')
         %br
-        = select_date @person.profile.birthday, :order => [:month, :day, :year], :start_year => 1930, :end_year => 2000
+        = select_date @person.profile.birthday, :prompt => true, :default => true, :order => [:month, :day, :year], :start_year => 1930, :end_year => 2000
 
       %h4
         = t('.your_bio')